The system'll crash when the users insmod crypto/tcrypto.ko with mode=155
( testing "authenc(hmac(sha1),cbc(aes))" ). It's caused by reuse the memory
of request structure.
In crypto_authenc_init_tfm(), the reqsize is set to:
[PART 1] sizeof(authenc_request_ctx) +
[PART 2] ictx->reqoff +
[PART 3] MAX(ahash part, skcipher part)
and the 'PART 3' is used by both ahash and skcipher in turn.
When the virtio_crypto driver finish skcipher req, it'll call ->complete
callback(in crypto_finalize_skcipher_request) and then free its
resources whose pointers are recorded in 'skcipher parts'.
However, the ->complete is 'crypto_authenc_encrypt_done' in this case,
it will use the 'ahash part' of the request and change its content,
so virtio_crypto driver will get the wrong pointer after ->complete
finish and mistakenly free some other's memory. So the system will crash
when these memory will be used again.
The resources which need to be cleaned up are not used any more. But the
pointers of these resources may be changed in the function
"crypto_finalize_skcipher_request". Thus release specific resources before
calling this function.
Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Reported-by: LABBE Corentin <[email protected]>
Cc: Gonglei <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Markus Elfring <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Message-Id: <20200123101000.GB24255@Red>
Signed-off-by: Longpeng(Mike) <[email protected]>
---
drivers/crypto/virtio/virtio_crypto_algs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index 5f8243563009..52261b6c247e 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -582,10 +582,11 @@ static void virtio_crypto_skcipher_finalize_req(
scatterwalk_map_and_copy(req->iv, req->dst,
req->cryptlen - AES_BLOCK_SIZE,
AES_BLOCK_SIZE, 0);
- crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
- req, err);
kzfree(vc_sym_req->iv);
virtcrypto_clear_request(&vc_sym_req->base);
+
+ crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
+ req, err);
}
static struct virtio_crypto_algo virtio_crypto_algs[] = { {
--
2.23.0
> The system'll crash when the users insmod crypto/tcrypto.ko with mode=155
> ( testing "authenc(hmac(sha1),cbc(aes))" ). It's caused by reuse the memory
> of request structure.
Wording adjustments:
* … system will crash …
* … It is caused by reusing the …
> when these memory will be used again.
when this memory …
> … Thus release specific resources before
Is there a need to improve also this information another bit?
Regards,
Markus
Hi Markus,
On 2020/5/26 15:19, Markus Elfring wrote:
>> The system'll crash when the users insmod crypto/tcrypto.ko with mode=155
>> ( testing "authenc(hmac(sha1),cbc(aes))" ). It's caused by reuse the memory
>> of request structure.
>
> Wording adjustments:
> * … system will crash …
> * … It is caused by reusing the …
>
>
>> when these memory will be used again.
>
> when this memory …
>
OK.
>
>> … Thus release specific resources before
>
> Is there a need to improve also this information another bit?
>
You mean the last two paragraph is redundant ?
'''
When the virtio_crypto driver finish skcipher req, it'll call ->complete
callback(in crypto_finalize_skcipher_request) and then free its
resources whose pointers are recorded in 'skcipher parts'.
However, the ->complete is 'crypto_authenc_encrypt_done' in this case,
it will use the 'ahash part' of the request and change its content,
so virtio_crypto driver will get the wrong pointer after ->complete
finish and mistakenly free some other's memory. So the system will crash
when these memory will be used again.
The resources which need to be cleaned up are not used any more. But the
pointers of these resources may be changed in the function
"crypto_finalize_skcipher_request". Thus release specific resources before
calling this function.
'''
How about:
'''
When the virtio_crypto driver finish the skcipher request, it will call the
function "crypto_finalize_skcipher_request()" and then free the resources whose
pointers are stored in the 'skcipher parts', but the pointers of these resources
may be changed in that function. Thus fix it by releasing these resources
befored calling the function "crypto_finalize_skcipher_request()".
'''
> Regards,
> Markus
>
---
Regards,
Longpeng(Mike)
>>> … Thus release specific resources before
>>
>> Is there a need to improve also this information another bit?
>>
> You mean the last two paragraph is redundant ?
No.
I became curious if you would like to choose a more helpful information
according to the wording “specific resources”.
Regards,
Markus
On 2020/5/26 17:01, Markus Elfring wrote:
>>>> … Thus release specific resources before
>>>
>>> Is there a need to improve also this information another bit?
>>>
>> You mean the last two paragraph is redundant ?
>
> No.
>
> I became curious if you would like to choose a more helpful information
> according to the wording “specific resources”.
>
> Regards,
> Markus
>
Hi Markus,
I respect your work, but please let us to focus on the code itself. I think
experts in this area know what these patches want to solve after look at the code.
I hope experts in the thread could review the code when you free, thanks :)
---
Regards,
Longpeng(Mike)
> I respect your work, but please let us to focus on the code itself. I think
> experts in this area know what these patches want to solve after look at the code.
I suggest to reconsider such a view.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=9cb1fd0efd195590b828b9b865421ad345a4a145#n102
Regards,
Markus
On Tue, May 26, 2020 at 05:24:03PM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
>
>
> On 2020/5/26 17:01, Markus Elfring wrote:
> >>>> … Thus release specific resources before
> >>>
> >>> Is there a need to improve also this information another bit?
> >>>
> >> You mean the last two paragraph is redundant ?
> >
> > No.
> >
> > I became curious if you would like to choose a more helpful information
> > according to the wording “specific resources”.
> >
> > Regards,
> > Markus
> >
> Hi Markus,
>
> I respect your work, but please let us to focus on the code itself. I think
> experts in this area know what these patches want to solve after look at the code.
>
> I hope experts in the thread could review the code when you free, thanks :)
Please note that you are responding to someone who is known to be a pain
in patch reviews and has been blocked by many kernel
developers/maintainers because they just waste people's time.
I suggest you all do the same here, and just ignore them, like I do :)
thanks,
greg k-h
> -----Original Message-----
> From: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> Sent: Tuesday, May 26, 2020 11:20 AM
> To: [email protected]
> Cc: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> <[email protected]>; LABBE Corentin <[email protected]>; Gonglei
> (Arei) <[email protected]>; Herbert Xu
> <[email protected]>; Michael S. Tsirkin <[email protected]>; Jason
> Wang <[email protected]>; David S. Miller <[email protected]>;
> Markus Elfring <[email protected]>;
> [email protected]; [email protected];
> [email protected]
> Subject: [PATCH v2 2/2] crypto: virtio: Fix use-after-free in
> virtio_crypto_skcipher_finalize_req()
>
> The system'll crash when the users insmod crypto/tcrypto.ko with mode=155
> ( testing "authenc(hmac(sha1),cbc(aes))" ). It's caused by reuse the memory of
> request structure.
>
> In crypto_authenc_init_tfm(), the reqsize is set to:
> [PART 1] sizeof(authenc_request_ctx) +
> [PART 2] ictx->reqoff +
> [PART 3] MAX(ahash part, skcipher part) and the 'PART 3' is used by both
> ahash and skcipher in turn.
>
> When the virtio_crypto driver finish skcipher req, it'll call ->complete callback(in
> crypto_finalize_skcipher_request) and then free its resources whose pointers
> are recorded in 'skcipher parts'.
>
> However, the ->complete is 'crypto_authenc_encrypt_done' in this case, it will
> use the 'ahash part' of the request and change its content, so virtio_crypto
> driver will get the wrong pointer after ->complete finish and mistakenly free
> some other's memory. So the system will crash when these memory will be used
> again.
>
> The resources which need to be cleaned up are not used any more. But the
> pointers of these resources may be changed in the function
> "crypto_finalize_skcipher_request". Thus release specific resources before
> calling this function.
>
> Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
> Reported-by: LABBE Corentin <[email protected]>
> Cc: Gonglei <[email protected]>
> Cc: Herbert Xu <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Jason Wang <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Markus Elfring <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Message-Id: <20200123101000.GB24255@Red>
> Signed-off-by: Longpeng(Mike) <[email protected]>
> ---
Acked-by: Gonglei <[email protected]>
Regards,
-Gonglei
> drivers/crypto/virtio/virtio_crypto_algs.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c
> b/drivers/crypto/virtio/virtio_crypto_algs.c
> index 5f8243563009..52261b6c247e 100644
> --- a/drivers/crypto/virtio/virtio_crypto_algs.c
> +++ b/drivers/crypto/virtio/virtio_crypto_algs.c
> @@ -582,10 +582,11 @@ static void virtio_crypto_skcipher_finalize_req(
> scatterwalk_map_and_copy(req->iv, req->dst,
> req->cryptlen - AES_BLOCK_SIZE,
> AES_BLOCK_SIZE, 0);
> - crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
> - req, err);
> kzfree(vc_sym_req->iv);
> virtcrypto_clear_request(&vc_sym_req->base);
> +
> + crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
> + req, err);
> }
>
> static struct virtio_crypto_algo virtio_crypto_algs[] = { {
> --
> 2.23.0
<20200123101000.GB24255@Red>
References: <[email protected]>
<20200123101000.GB24255@Red>
Hi
[This is an automated email]
This commit has been processed because it contains a "Fixes:" tag
fixing commit: dbaf0624ffa5 ("crypto: add virtio-crypto driver").
The bot has tested the following trees: v5.6.14, v5.4.42, v4.19.124, v4.14.181.
v5.6.14: Build OK!
v5.4.42: Failed to apply! Possible dependencies:
eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
v4.19.124: Failed to apply! Possible dependencies:
eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
v4.14.181: Failed to apply! Possible dependencies:
500e6807ce93 ("crypto: virtio - implement missing support for output IVs")
67189375bb3a ("crypto: virtio - convert to new crypto engine API")
d0d859bb87ac ("crypto: virtio - Register an algo only if it's supported")
e02b8b43f55a ("crypto: virtio - pr_err() strings should end with newlines")
eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
--
Thanks
Sasha
On Tue, May 26, 2020 at 02:11:37PM +0000, Sasha Levin wrote:
> <20200123101000.GB24255@Red>
> References: <[email protected]>
> <20200123101000.GB24255@Red>
>
> Hi
>
> [This is an automated email]
>
> This commit has been processed because it contains a "Fixes:" tag
> fixing commit: dbaf0624ffa5 ("crypto: add virtio-crypto driver").
>
> The bot has tested the following trees: v5.6.14, v5.4.42, v4.19.124, v4.14.181.
>
> v5.6.14: Build OK!
> v5.4.42: Failed to apply! Possible dependencies:
> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>
> v4.19.124: Failed to apply! Possible dependencies:
> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>
> v4.14.181: Failed to apply! Possible dependencies:
> 500e6807ce93 ("crypto: virtio - implement missing support for output IVs")
> 67189375bb3a ("crypto: virtio - convert to new crypto engine API")
> d0d859bb87ac ("crypto: virtio - Register an algo only if it's supported")
> e02b8b43f55a ("crypto: virtio - pr_err() strings should end with newlines")
> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>
>
> NOTE: The patch will not be queued to stable trees until it is upstream.
>
> How should we proceed with this patch?
Mike could you comment on backporting?
> --
> Thanks
> Sasha
On 2020/5/31 17:21, Michael S. Tsirkin wrote:
> On Tue, May 26, 2020 at 02:11:37PM +0000, Sasha Levin wrote:
>> <20200123101000.GB24255@Red>
>> References: <[email protected]>
>> <20200123101000.GB24255@Red>
>>
>> Hi
>>
>> [This is an automated email]
>>
>> This commit has been processed because it contains a "Fixes:" tag
>> fixing commit: dbaf0624ffa5 ("crypto: add virtio-crypto driver").
>>
>> The bot has tested the following trees: v5.6.14, v5.4.42, v4.19.124, v4.14.181.
>>
>> v5.6.14: Build OK!
>> v5.4.42: Failed to apply! Possible dependencies:
>> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>>
>> v4.19.124: Failed to apply! Possible dependencies:
>> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>>
>> v4.14.181: Failed to apply! Possible dependencies:
>> 500e6807ce93 ("crypto: virtio - implement missing support for output IVs")
>> 67189375bb3a ("crypto: virtio - convert to new crypto engine API")
>> d0d859bb87ac ("crypto: virtio - Register an algo only if it's supported")
>> e02b8b43f55a ("crypto: virtio - pr_err() strings should end with newlines")
>> eee1d6fca0a0 ("crypto: virtio - switch to skcipher API")
>>
>>
>> NOTE: The patch will not be queued to stable trees until it is upstream.
>>
>> How should we proceed with this patch?
>
> Mike could you comment on backporting?
>
Hi Michael,
I will send V3, so I will resolve these conflicts later. :)
>> --
>> Thanks
>> Sasha
>
> .
>
---
Regards,
Longpeng(Mike)